Performance enhancement of Underwater Wireless Sensor Networks (UWSNs) in terms of throughput maximization, energy conservation and Bit Error Rate (BER) minimization is a potential research area. However, limited available bandwidth, high propagation delay, highly dynamic network topology, and high error probability leads to performance degradation in these networks. In this regard, many cooperative communication protocols have been developed that either investigate the physical layer or the Medium Access Control (MAC) layer, however, the network layer is still unexplored. More specifically, cooperative routing has not yet been jointly considered with sink mobility. Therefore, this paper aims to enhance the network reliability and efficiency via dominating set based cooperative routing and sink mobility. The proposed work is validated via simulations which show relatively improved performance of our proposed work in terms the selected performance metrics.

Underwater environment suffers from a number of impairments which effect reliability and integrity of data being transmitted. Cooperative transmission is well known for reliable data transfer. Hence, cooperative routing can be implemented in Underwater Wireless Sensor Networks (UWSNs) in order to reduce the impact of existing link impairments on transmitted data. Cooperative routing involves data transmission via partner node (relay/destination node) towards sink. Selection of partner node for cooperative routing is to be performed on basis of a certain criterion so that effective results can be achieved. In this paper, two different partner node selection criteria are implemented and compared. We consider source node's depth threshold (dth), potential relay/destination nodes's depth, residual energy and Signal to Noise Ratio (SNR) of the link connecting source node with potential relay/destination node as selection parameters. One criterion considers depth and residual energy while the other also takes link's SNR into account along with depth and residual energy. SNR based criterion is proved to outperform the one involving only depth and residual energy information. Simulation results show that the SNR based criterion achieves better results with respect to stability period and Packet Acceptance Ratio (PAR) along with reduced delay and packet drop.

Energy Hole is the major problem in the efficiency of Wireless Sensor Networks (WSNs). A routing protocol MASEHA: Multi-hop communication using Active and Sleep nodes for Energy Hole Avoidance is proposed in this research paper to overcome the energy hole problem. Taking the concept of Active and sleep mode of nodes, we propose that the network is divided into active and sleep nodes. Half of the sleep nodes are turned on when the first node dies and remaining sleep nodes are activated after the death of tenth node. We have achieved balanced stability, increased sensing period of nodes and balanced energy consumption. Further, MASEHA uses dynamic clustering, divides the network into small sub-areas and uses uniform number of CHs throughout the network. Selection of CHs is done on the basis of maximum energy and minimum distance multi-hop communication is utilized in our paper. Simulation results show that these aspects help in out performing our proposed protocol with the existing protocols.

Underwater Wireless Sensor Networks (UWSNs) support various applications like pollution monitoring, tsunami warnings, offshore exploration, tactical surveillance, etc. Distinctive features of UWSNs like low available bandwidth, large propagation delay, highly dynamic network topology, and high error probability pose many challenges for designing efficient and reliable communication protocols. In this paper, we propose an extension of IAMCTD (Improved Adaptive Mobility of Courier nodes in Threshold-optimized DBR protocol for UWSNs) that focuses on enhancing network reliability and throughput for critical-range based applications. Our scheme avoids control overhead that was present in IAMCTD for implementing changes in depth threshold. The movement pattern of courier nodes along with reducing communication burden on nodes increases throughput as well. Additionally, stability period is improved and node density per round remains comparatively high improving the overall network reliability. Based on the comprehensive simulations using MATLAB, we observe that our scheme improves the performance in terms of throughput and stability period. Moreover, comparatively higher network density per round is maintained and end-to-end delay is stabilized throughout the network lifetime.

Network efficiency and reliability in terms of high throughput, energy conservation, low bit error rate (BER) and reduced delay are pre-requisites for many applications in Underwater Wireless Sensor Networks (UWSNs). However, distinctive features of UWSNs like low available bandwidth, large propagation delay, highly dynamic network topology, and high error probability pose many challenges for devising efficient and reliable communication protocols. In this paper, we therefore propose a protocol that focuses on enhancing network reliability and efficiency using cooperative routing and sink mobility. Many cooperative communication protocols have been developed which investigate the physical and MAC layer aspects to improve link efficiency in harsh underwater environment, however, at network layer, it is still unexplored. Similarly, cooperative routing is not yet collaborated with sink mobility. In this paper, Cooperative routing is implemented at network layer along with sink mobility. Potential relay and destination nodes for cooperative routing are selected on the basis of their depth as well as residual energy information. Data from source node is forwarded towards the destination node via relay nodes in a cooperative manner. Sink mobility further improves the results by directly gathering data from nodes. Based on the comprehensive simulations implemented in MATLAB, we observe that our scheme improves the performance in terms of network lifetime, energy efficiency and throughput along with reducing delay and BER.

Underwater Wireless Sensor Networks (UWSNs) support various applications like pollution monitoring, tsunami warnings, offshore exploration, tactical surveillance, etc. Distinctive features of UWSNs like low available bandwidth, large propagation delay, highly dynamic network topology, and high error probability pose many challenges for designing efficient and reliable communication protocols. In this paper, we propose an extension of IAMCTD (Improved Adaptive Mobility of Courier nodes in Threshold-optimized DBR protocol for UWSNs) that focuses on enhancing network reliability and throughput for critical-range based applications. Our scheme avoids control overhead that was present in IAMCTD for implementing changes in depth threshold. The movement pattern of courier nodes along with reducing communication burden on nodes increases throughput as well. Additionally, stability period is improved and node density per round remains comparatively high improving the overall network reliability. Based on the comprehensive simulations using MATLAB, we observe that our scheme improves the performance in terms of throughput and stability period. Moreover, comparatively higher network density per round is maintained and end-to-end delay is stabilized throughout the network lifetime. c